By Ethan Lou

(Reuters) - The first chief digital officer of TMX Group Ltd's Toronto Stock Exchange (TSX) has left the organization to devote more time to his venture based on blockchain, the technology behind the bitcoin cryptocurrency, the executive said on Monday.

Anthony Di Iorio, founder of the Bitcoin Alliance of Canada and a co-founder of Ethereum, a blockchain-based computing platform, was hired by Canada's largest stock exchange in January.

He left in September to focus on Jaxx, a universal "wallet" for holding cryptocurrencies and "tokens" that facilitate transactions in blockchain-based applications, Di Iorio said in a phone interview.

Di Iorio's hire at TSX came as stock exchanges were embracing blockchain, which allows Bitcoin users to conduct secure transactions without middlemen, as they seek to diversify and boost profit margins. When used to issue securities, the technology could potentially remove the need for clearing houses.

Jean Desgagne, chief executive of TMX's Global Enterprise Services, said in March the technology could make operations "better, faster, cheaper."

At the time, he declined to discuss specific potential uses TSX may have for blockchain, a matter that is still unclear.

TMX said it no longer has someone using that title, and that John Lee, a vice president of innovation and enterprise delivery, is now leading development of "our capability in emerging technologies, and exploring the potential of new areas such as blockchain."

Blockchain's distributed-ledger system allows users to conduct secure transactions with each other without the need for middlemen or central oversight. While long associated with cryptocurrencies such as bitcoin, blockchain can also be used for running applications with a wide range of purposes.

Users usually need separate wallet programs to hold different cryptocurrencies and tokens for applications built on blockchain. Jaxx, launched in February, seeks to eliminate that need.

"Jaxx really started taking off over the past months, and that's really where my passion is," Di Iorio said. "I prioritize the things that are really important to me, and that's the No. 1 thing."

Di Iorio said he and TSX parted on good terms. He declined to elaborate on the stock exchange's plans with regard to blockchain.

In January the Australian stock exchange said it had enlisted a blockchain startup to develop a new trade settlement system.

Nasdaq in the United States used the technology last year to issue securities to an unidentified private investor. In February, Nasdaq said it was developing a blockchain-based shareholder voting system for its Estonian stock exchange.

(Reporting by Ethan Lou in Calgary, Alberta; Additional reporting by Alastair Sharp in Toronto; Editing by Lisa Shumaker and Paul Tait)